Pseudo soldering components may result in multiple problems on an iPhone. This soldering issue of chips may be related to several reasons:
1. Manufacturing defect when leaving factory;
2. Misoperation when running a logic board repair;
3. Bad habits of its users etc.
This time we will share you with an iPhone X no ringtone sound repair case caused by pseudo soldering of the motherboard after being dropped.
The phone features a broken screen and a deformed housing.
Get a new display assembly installed and test. The phone turns on normally. After a series of test, we found out that there is no output sound when selecting a ringtone. Yet the sound works fine with a headphone plugged in.
The preliminary judgment is that the audio circuit is in normal condition. It’s just that the bottom speaker is not working. Remove the display assembly and disconnect the battery. Disconnect the charging port flex cable.
Run diode mode measurement of the DOCK connector. The measured value is normal. Which indicates that the bottom speaker is in normal condition.
Run diode mode measurement
Continue to measure the connector on motherboard. The relevant circuit of one Pin has been open-circuited.
measure the connector on motherboard
Remove the upper layer with Hot Air Gun. There are multiple missing pins on the upper layer.
Judging by this, the phone has been dropped. Which resulted in pseudo soldering of the motherboard and detachment of pins. Remove tins on cylinders and bonding pads of the upper layer. Clean with PCB Cleaner afterward.
Remove tins on cylinders and bonding pads
Run diode mode measurement of Pin S162 and Pin S163. The measured value is normal.
Judging by this, the open-circuited condition is caused by pseudo soldering of cylinders around the edge of the lower layer.
Get the motherboard installed to the testing kit and test. Current reading on the ammeter is normal. Go to Settings>Sounds&Haptics>Ringtone. Select a default ringtone. Normal output sound this time.
We can confirm now that the fault is caused by pseudo soldering of cylinders around the edge of the lower layer. Now we can solder the two layers together. Before soldering, treat Pin S166 with jumper wiring.
Next, let’s get the lower layer reballed. And re-solder the motherboard.
Assemble the phone and test. Go to Settings>Sounds&Haptics>Ringtone. Select a default ringtone, normal output sound this time. Fault cleared.
Attaching the video for more details about the iPhone X Bottom Speaker Not Working Repair - Pseudo Soldering
* Communication Maintenance Power Supply
* Digital Soldering Iron Rework Station
* Digital Hot Air Rework Station - 861DW
* Digital Multimeter* Multifunctional PCB Holder for iPhone X
* Straight Tweezer
* Curved Hook Tweezer
* High Purity Rosin Soldering Flux
* Stainless Steel BGA Scraper
More Guides About iPhone X Series, You Can Read
Apr 23, 2021
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